You said...…….
"as expressed in the Bible itself—is Scripture plus apostolic tradition, as manifested in the living teaching authority of the Catholic Church".
Now, where in the Bible can we find that opinion so that we can verify it?
If there are No Scriptures which verify your opinion then that is exactly what your comment is my dear friend.
My dear friend Major1, Catholicanswers.com explains it quite nicely for you here: (take special notice of the last paragraph)
"We cling tightly to this tradition because it's true, for starters, and because all Christians are commanded to do so by Paul in 1 Corinthians 11:2 and 2 Thessalonians 2:15. For biblical corroboration look at Acts 1:21-26, where you'll see the apostles, immediately after Jesus' Ascension, acting swiftly to replace the position left vacant by Judas's suicide.
They prayed for guidance, asking God to show them which candidate was "chosen to take the place in this apostolic ministry from which Judas turned away." After choosing Matthias they laid hands on him to confer apostolic authority.
Look at 1 Timothy 1:6 and 4:14, where Paul reminds Timothy that the office of bishop had been conferred on him through the laying on of hands. Notice in 1 Timothy 5:22 that Paul advises Timothy not to be hasty in handing on this authority to others. In Titus Paul describes the apostolic authority Titus had received and urges him to act decisively in this leadership role.
Lastly, please do better homework on early Christian writings. The testimony of the early Church is deafening in its unanimous (yes, unanimous) assertion of apostolic succession. Far from being discussed by only a few, scattered writers, the belief that the apostles handed on their authority to others was one of the most frequently and vociferously defended doctrines in the first centuries of Christianity."
Here is another article from Catholicanswers.com that may be of interest to you;
"Full Question:
Is apostolic Tradition, apart from the Bible, inerrant or can it contain errors?
Answer:
It is inerrant, and because it is inerrant, apostolic Tradition will never contradict the Bible, which is also inerrant. Human traditions may contain mistakes, but apostolic Tradition does not. Any teaching that the apostles authoritatively passed down to the Church is inerrant, irrespective of whether it is written down.
The key to telling which Traditions are apostolic and which are merely human is the same as they key to telling which writings are apostolic and which are merely human. It is the magisterium that recognizes the "canon" of apostolic Tradition, just as it recognized the canon of apostolic Scripture.
Scripture and Tradition are important because anything the apostles authoritatively passed down to the Church, whether written or not, is inerrant. The Catechism of the Catholic Church states,
Sacred Tradition and Sacred Scripture, then, are bound closely together . . . flowing out from the same divine well-spring, [they] come together in some fashion to form one thing and move towards the same goal.
As a result the Church, to whom the transmission and interpretation of Revelation is entrusted, "does not derive her certainty about all revealed truths from the holy Scriptures alone. Both Scripture and Tradition must be accepted and honored with equal sentiments of devotion and reverence." (CCC 80, 82, citing Vatican II, Dei Verbum 9)
Most of apostolic Tradition contains the same material that is found in apostolic Scripture, only in a different form. This makes the two useful for interpreting each other because they contain the same material phrased different ways.
For example, the doctrine of baptismal regeneration is found several places in Scripture, such as in John 3:5, where Jesus says, "Unless one is born of water and the Spirit, he cannot enter the kingdom of God." But because Jesus uses the metaphor for baptism, "born of water and the Spirit," many Protestants have tried to deny that it is a reference to baptism at all and have claimed that baptismal regeneration is false.
This is disproven through the apostolic Tradition preserved in the writings of the Church Fathers, who not only teach baptismal regeneration but also unanimously interpret John 3:5 as referring to baptism (see "The Fathers Know Best" column in the October 1994 issue of This Rock)."
Have a Blessed Day my friend